The Student Room Group

Maths gcse question

Please could I have help on this question? I have attached the question and my working below but I do not know what I did wrong?
Thank you!36EEC476-C21E-4130-A015-AA8BD8483FF8.jpeg8EC305E3-9D89-4710-A508-FDA4C24C1A18.jpeg
(edited 1 year ago)
Original post by Ashirs
Please could I have help on this question? I have attached the question and my working below but I do not know what I did wrong?
Thank you!36EEC476-C21E-4130-A015-AA8BD8483FF8.jpeg8EC305E3-9D89-4710-A508-FDA4C24C1A18.jpeg


My assumption is where you have written 2p, you mean 2^p.

If so, I’d assume you are on the right track. Can you try collecting like terms together?
(edited 1 year ago)
Reply 2
your last part is wrong
2^p*2^p=4^2p
thus, 4^p(1^p-1)
(edited 1 year ago)
Reply 3
Original post by esam12
your last part is wrong
2^p*2^p=4^2p
thus, 4^p(1^p-1)


Sorry would 2^p*2^p=2^2p?
Reply 4
Original post by TypicalNerd
My assumption is where you have written 2p, you mean 2^p.

If so, I’d assume you are on the right track. Can you try collecting like terms together?

Sorry yes that is what I meant.
So I I grouped the like terms would it not be 2^2p-2^p+1 because -2^p-2^p is the same as that multiplied by 2 so it would be 2^p times 2^1 so 2^p+1 but how would I factorise what is given in the question out?
Reply 5
y r right
Start by doing a difference of two squares on N.
(edited 1 year ago)
Original post by Ashirs
Sorry yes that is what I meant.
So I I grouped the like terms would it not be 2^2p-2^p+1 because -2^p-2^p is the same as that multiplied by 2 so it would be 2^p times 2^1 so 2^p+1 but how would I factorise what is given in the question out?

Start by taking out a factor of 2^p.

After factorising, what do you notice about your other factor? Is it odd or even? How might that help?
(edited 1 year ago)
Write 2^p in terms o f k. Then do 2^(p+1). Then as suggested earlier, use DOS on N
Reply 9
Original post by mqb2766
Start by doing a difference of two squares on N.


Ohh yes I used this method and it works now, I got 2^p+1(2^p-1 -1) Thank you!
(edited 1 year ago)
Original post by Ashirs
Ohh yes I used this method and it works now, I got 2^p+1(2^p/2 -1) Thank you!


I think it should be 2^(p-1) rather than 2^(p/2), but the idea is right.

You could expand and then factorise, but a difference of two squares keeps things factorised and is hinted at in the way the expressions are formed.
Reply 11
Original post by mqb2766
I think it should be 2^(p-1) rather than 2^(p/2), but the idea is right.

You could expand and then factorise, but a difference of two squares keeps things factorised and is hinted at in the way the expressions are formed.

Yes sorry thank you!!
Original post by Ashirs
Yes sorry thank you!!


You may have meant (2^p)/2 which was actually right.

Quick Reply

Latest